Selector mechanism for a motor vehicle transmission

Abstract

A rotatable selector mechanism for a motor vehicle transmission has a selector knob rotatable in a housing to select an operating mode of the transmission among a number of selector positions indicated by a label (P, R, N, D, M). The selector mechanism further includes a detent plate which cooperates with a detent pin for maintaining the selector knob in each of positions. The detent plate is connected to position sensors for generating selector signals to a transmission control unit which supplies control signals to an actuator for operate the transmission according to the operating mode selected. The detent plate is also associated to the selector knob and to a drive correction means by means of clutch devices respectively to engage the detent plate to one of the selector knob and the drive correction means. The clutch devices and the drive corrections means are controlled by the transmission control unit to move the detent plate from a selector position selected by the driver to another selector position representative of the operating mode of the transmission by means of the drive correction means without moving the selector knob. The selector knob further includes an illuminated pointer constituted by one of several LEDs controlled by the transmission control unit so as to change the LED illuminated in front of the label according to the position of the detent plate when the latter has been moved by the drive correction means in order to indicate the operating mode of the transmission.

1. A method of controlling a selector mechanism of a motor vehicle having a transmission, a transmission control unit, at least one sensor for sensing a position of a rotary selector on the selector mechanism, an index mechanism for maintaining a rotary handle of the selector mechanism in one of a predetermined number of selector positions corresponding to one of a predetermined number of transmission operating modes, and a selector correction mode device, and a clutch mechanism engaging the rotary selector to one of the rotary handle and the selector correction mode device, wherein the clutch mechanism and the selector correction mode device are controlled by the transmission control unit to move the rotary selector from a selector position selected by the driver through the rotary handle to another selector position representative of the operating mode of the transmission by means of the selector correction mode device without moving the rotary handle, the method comprising the steps of:
 determining an operational state of the vehicle and providing data related to said operational state to the transmission control unit; 
 receiving a signal from the sensors indicating whether a selector mode is available or unavailable; 
 if the selector mode is unavailable the transmission control unit operates the clutch mechanism to engage the rotary selector to the selector correction mode device and disengage the rotary selector from the rotary handle; and 
 sending a command to the selector correction mode device to return the rotary selector to the previous gear position. 
 
     
     
       2. The method of  claim 1  wherein the selector mechanism further comprises a dynamic indicator which in use is arranged to indicate the operating mode of the transmission, the method including the further step of sending a command from the transmission control unit to the dynamic indicator to indicate the mode of the transmission according to the motion of the rotary selector. 
     
     
       3. The method of  claim 2  wherein the dynamic indicator of the selector mechanism further comprises an illuminated pointer and an arrangement of illuminated labels indicating the selector mode, the method including the further step of the transmission control unit sending a command to turn the illuminated pointer off and a command to illuminate the label of the current selector mode. 
     
     
       4. The method of  claim 1  when the selector mechanism further comprises a retractor actuator controlled by the transmission control unit to displace the rotary handle between an active position where it can be manually moved between the selector positions by the driver of the vehicle, and an inactive position in which it is retracted inside the housing where it cannot be readily moved by the driver, the method further including the step of sending a command from the transmission control unit to the retractor actuator to move the rotary switch to the active position when the engine is running and to move the rotary switch to the inactive position when the engine is stopped. 
     
     
       5. The method of  claim 4  further including the step of upon the transmission control unit receiving a failure signal, the transmission control unit sending a command to the retractor actuator to move the selector towards the inactive position from the active position.